Step 2: Setup the docker-compose environment

The goal for Step 2: Create a docker-compose.yml file with a defined volume for your Flask Quotes application.

Note

We’ll use port 20854 for the reverse proxy.

Table of Contents

• Step 2: Setup the docker-compose environment

  • 2.1. Create the docker-compose.yml file and add support files

  • 2.2. Create the reverse proxy

2.1. Create the docker-compose.yml file and add support files

1. Create a folder for your Flask Quotes application called flask-quotes and create an empty docker-compose.yml file.

   cd ~
   mkdir flask-quotes
   cd flask-quotes
   touch docker-compose.yml
   

2. Verify the information in the Dockerfile.

   Before you create your docker-compose.yml file, you will need information from your Dockerfile. Open it to verify that nothing has changed.

   WORKDIR /app    ----> For the volume   (where code files are)
   EXPOSE 5000     ----> For port mapping (the port that that the Python web server is running on)
   

3. Write the docker-compose.yml file to use python/flask:dev and with defined a volume called quotes-app or something similar Here is your template (fill in the data from your Dockerfile):

   Destination volume

   The working directory (WORKDIR) defined in the image

   Destination port

   The port (EXPOSE) that the Python web server runs on

   Tip

   EXPOSE is a best-practice marker only. The actual port is defined in the index.py file

   app.run(host="0.0.0.0", port=int("5000"), debug=True)
   

   docker-compose.yml template

   version: '3'
   
   services:
      flask:
        image: python/flask:dev
        volumes:
          - ./quotes-app:/_____
        ports:
          - 20854:____
        restart: always
   

4. Now, can create the volume with the index.py to create a basic hellow world Flask app, as a first-step for all new projects. 🧑‍💻🙂

   # All code files will go here
   mkdir quotes-app
   
   # copy the index.py file that you put inside of python/flask:dev
   cp ~/flask-dev-image/index.py quotes-app/
   
   # Your directory should look like this:
   sysadmin@test2:~/flask-quotes$ tree
   .
   ├── docker-compose.yml
   └── quotes-app
       └── index.py
   
   1 directory, 2 files
   

5. Verify the config, start the container, and verify that it returns the expected result:

   sysadmin@test2:~/flask-quotes$
   sysadmin@test2:~/flask-quotes$ docker-compose config
   services:
     flask:
       image: python/flask:dev
       ports:
       - 20854:5000/tcp
       restart: always
       volumes:
       - /home/sysadmin/flask-working/flask-quotes/app:/app:rw
   version: '3.0'
   
   sysadmin@test2:~/flask-quotes$ docker-compose up -d
   Starting flaskquotes_html_1 ...
   Starting flaskquotes_html_1 ... done
   sysadmin@test2:~/flask-quotes$
   sysadmin@test2:~/flask-quotes$ curl localhost:20854
   Hello World! Привет, мир! Сәлем Әлем! ¡Hola Mundo! नमस्ते दुनिया! 안녕하세요! Hallo Welt! 你好，世界!
   sysadmin@test2:~/flask-quotes$
   

2.2. Create the reverse proxy

1. Create sub-domain pandoc.example.com

2. Create your Reverse Proxy using these settings

   • server_name quotes.example.com;

   • proxy_pass http://localhost:20854;

3. Enable the Nginx Site

4. Restart Nginx

5. Verify using curl or using the web browser.